(1) Field of the Invention
The present invention relates to an apparatus and a method for extending memory in a computer printer or other computer output device. More particularly, the present invention relates to an apparatus and a method for extending the memory in a computer printer or other output device using a computer network and a network file system protocol.
(2) Prior Art
In the computing industry, it has become quite common to use a computer network to extend available memory on computer systems. A computer network is the interconnection of two or more computer systems. The interconnection is accomplished through some network medium such as through radio waves, wires, fiber optic cables, etc. A network medium is used to send messages between the computer systems. The messages being sent between the computers conform to a specific form known as a protocol.
Network protocols have been used to extend the amount of memory available in a computer. For example, network protocols have been used to extend the space available for the file system storage of a computer. NFS (Network File System) protocol designed by Sun Microsystems, Inc. is one such network protocol. The method for extending available computer memory using a network is well known in the art.
As with computers, computer printers also require the use of memory. A computer printer is a device which transforms information from a computer system into markings on a physical medium such as on a sheet of paper. During the transformation of information, the printer may need additional memory. For example, processing of a complex document requires a substantial amount of memory. An example of a complex document includes, a document containing text with different font styles, different character size, drawings intermingled with text, etc. However, presently available laser printers or other continuous raster scan devices are equipped with limited memory space with no source of auxiliary memory. If a printer memory becomes full before the data to be printed is completely transferred to the printer, the printer will halt and typically produce an error message. Thus, the limitation on available memory leads to failures in printing.
Providing additional memory space is especially relevant for laser printers or other continuous raster scan devices which typically require that all bit mapped data representing a page to be printed is in memory. This is due to the fact that once a print engine of a printer begins operation, it runs at a constant speed and the print engine cannot stop or slow down to wait for additional bit mapped data to be provided.
Given that presently available printers have limited memory space, it is desirable to have a method and an apparatus for extending the amount of memory available to a printer using a network and a set of network protocols.